This thesis analyses three aspects of the enrollment of foreign children in the Catalan educational system as a result of the international migration boom from the beginning of the 21st century. First, the research analyzes the changes in the composition and the structure of the enrolled population in both public and charter educational centers from a demographic perspective. Second, the geographic dimension of the phenomenon will be incorporated in the study of school segregation and its possible relation to residential segregation. And finally, the research will consider determinants of the educational attainment of the foreigners. The empirical investigation is carried out for the period between the school years 2000/01 and 2007/08. Using data from the Non-university Enrollment Statistics and the Continuous Register, the research showed that there is an imperfect match between the residential and the enrolled population at compulsory ages that could be influenced by the nationality acquisition processes. With respect to the variables affecting the school segregation levels, the evidence suggests that the immigrants’ settlement patterns are not being reflected at school strata level. Also, if spatial interactions among origins are considered as a sign of the social integration of migrants, under the revealed preferences assumption the distribution of the enrolled would also be a reflection of the households’ preferences. Finally, the research explores the possible determinants of educational attainment. First, by exploring data from the 1991 and 2001 Census, results suggest that parental education is a determinant of educational attainment but final choice will be influenced by economic decisions given the relative costs of studying. Second, we analyzed the incidence of post-migration investments in education and the educational profile of the Catalan population by origin. The estimations show that there are regional differences in the investments but also in the human capital portability of the foreign-born. Overall results suggest the segmented assimilation of the foreign population.